Antenna system



Nov. 12, 1929. cs. A. MATHIEU ANTENNA SYSTEM 3 Sheets-Sheet Filed Feb. 3, 1927 u E M .A M R n 0 .Nu fl N l.- N M r R W 0 mw 1 n G Nov. 12, 1929. G. A. MATHIEU ANTENNA SYSTEM Filed Feb. 5 1927 5 Sheets-Sheet 2 A A A A 7A] mama [ii I 7- I I uumm 7 mm] I mmmx 7 7 N WI INVENTOR GASTON ADELIN MATHIEU TTORNEY Nov. 12, 1929. G. A. MATHIEU 1,735,033

ANTENNA SYSTEM Filed 1.927 3 Sheets-Sheet 3 my. a

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T me A 229.7 M i WI 1 W1 INVENTOR GASTON ADELIN MATH lEU TORNEY' Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE GASTON ADELIN MATHIEU, orronnon, ENGLAND, ASSIGNOR TO RADIO CORPORATION or AMERICA, A CORPORATION or DELAWARE I ANTENNA SYSTEM Application filed February 3, 1927, Serial No. 165,535, and in Great Britain February 27, 1926.

This invention relates to wireless receiving aerial systems and circuits therefor, and more particularly to a feeder arrangement by means of which energy received by a plurality of aerials may be rendered cumulative and fed to a terminal tank circuit which may constitute the input circuit of a wireless receiver.

According to this invention the energy received upon a pair or a plurality of pairs of aerials is rendered cumulative for each pair in intermediate or auxiliary feeders by means of twin transformers, the energy in pairs of the said feeders being similarly rendered cumulative in further intermediate or auxiliary feeders, and so on, until the energy received upon all the aerials is rendered cumulative in a single receiving or terminal tank circuit.

Preferably the twin transformers each comprise two primaries and two secondaries, and a capacitative reactance such as will substantially balance the inductive reactance of one of the secondaries.

In one arrangement as applied to a receiving installation having two aerials, the energy received upon each aerial is fed into a twin wire auxiliary feeder, preferably through aerial transformer. In general, such aerial transformers will be necessary not only to provide coupling but also owing to the fact that the surge impedances f the auxiliary feeders will probably differ widely from the impedances of their associated aerials. These aerial transformers may be conveniently formed as auto-transformers, the twin wires of the auxiliary feeders being tapped upon an inductance in the aerial, circuit, and

the said aerial being earthed preferably mid-i way between the tappings. The two auxiliary feeders are each connected to one of the primaries of a twin transformer having two primaries and two secondaries, and the secondaries of the said twin transformer are connected in series through a condenser of such size that its capacitative reactance substantially balances the inductive reactance of one secondary winding, and supplies energy to a twin wire main feeder which in turn supplies energy to the tank circuit. The

twin wires of one of the auxiliary feeders should be crossed over between its associated aerial and the twin transformer, so that the said transformer will add vectoriallyfthe voltages fed to it from the auxiliary feeders.

The ratio of transformation of the twin transformers should be such as to provide for the correct impedance of the main working in series at the junction point. For example, if the surge impedances of the auxiliary feeders and the main feeder are equal, the transformer should have a step down ratio of 2: 1 towards the tank circuit. Similarly, the effective impedance of the tank circuit should be substantially equal to the surge impedance of the main feeder, so as to avoid reflection and obtain maximum transfer into the said circuit.

. If desired, in place of twin wire auxiliary feeders there may be employed auxiliary feeders of any other suitable type.

The invention may be extended to any number of pairs of aerials. For example, in the case of four aerials, there will be four aerial transformers supplying four auxiliary feeders whose energy is rendered cumulative in pairs, by means of two twin transformers which in turn supply two further auxiliary feeders which transfer their energy through another twin transformer into the main feeder and tank circuit.

The invention will be further explained and illustrated with reference to the accompanying drawings, of which Figure 1 is a connecting cables. The transformers T are required each to act as coupling means and alsoto match the impedance of its associated aerial A with the surge impedance of its associated connectin cable W transformers T are each require to add vectorially thevoltages transmitted to it by its associated cables N while the transformer 'I is required to add vectcrially the voltages transmitted to it by its associated cables The arrangement is shown in greater diagrammatic detail in Figure 6, in which it will be seen that the trans-formers. T and T, aretwin transformers. In each of these transformers the secondaries are connected in series through condensers C which are adjusted to balance the inductive reactance of one of the second ary windings, so that by suitably adjusting the ratio of transformation of the transformers T maximum transference of energy from the aerials may be obtained while the whole system is balanced.

Figure 7 illustrates two aerials of a receiving aerial system feeding via transformers T through a twin transformer T and thence through an intermediate feeder and thence ultimately to a tank circuit.

Examination of the arrangements shown in Figures 1, 6 and 7, will reveal that they constitute in effect perfectlybalanced three wire systems with the neutral wire removed. This will appear more clearly from Figures 2, 3, l and 5. Referring to Figure 2, this shows the aerials represented as alternators A each feeding through a transformer T and cablesWV to a receiver Z. Assuming the transformer T cables W and receivers Z to be similar, the same power can be transmitted by means of two three wire systems as shown in Figure 3, or a single three wire system as shown in Figure l. In the double system of Figure 3 the voltage across the outer lines will he obviously equal to the sum of the voltages across two of the receivers Z, while in the system of Figure 4 the voltage across the outer lines will similarly be equal to the sum of the voltage across all the receivers Z.

In both cases, assuming perfect balance, no current will flow in the neutral wires N and these wires may therefore be removed. This leads logically to the arrangement shown in Figure 5, in which the neutral wires are removed, and to the already described arrangements of Figures 6 and 7. r r

Obviously systems in accordance with this invention may be employed for transmitting as well as for receivin 7 Having thus particularlydescribed the nature of my invention what I claim is 1. A wireless system comprising a plurality of pairs ofa'erials, intermediate and auxiliary feeders, a terminal circuit and means comprising twin transformers each of which has two primaries and two secondaries the latter being connected in series for rendering l tive the energyfrom each pair of aci said intermediate or auxiliary feedand similar means for rendering cumuive the energy from pairs of intermediate auxiliary feeders and so on until the enei fronr'or to all the aerial is rendered cumulative said terminal circuit.

2. A wireless system comprising a plurality of pairs of aerials, intermediate and auxiliary feeders, a terminal circuit, means comprising twin transformers each having two primaries and two secondaries, the latter being connected in series through a capacitive reactance such hat the inductive reactance of one secondary is substantially balanced, for rendering cumulative the energy for each pair of said aerials in said intermediate or auxiliary feeders, and means for rendering cumulative the energy from pairs of intermediate and auxiliary feeders and so on until the energy from or to all the aerials has been cumulated in said terminal circuit.

3. A wireless system comprising a plurality of pairs of aerials, an auto-transformer associated with each aerial, twin transformers each having a pair of primaries coupled through said auto-transformers to each pair of aerials and a pair of secondaries connected in series, a twin transformer associated with the first mentioned transformers for rendering cumulative the energy from each pair of aerials, and a utilization circuit associated with the last mentioned transformer.

a. A wireless system comprising a plurality of pairs of aerials, intermediate or auxiliary feeders, a single terminal tank circuit, means comprising twin transformers each having two primaries and two secondaries the latter being connected in series through a condenser for rendering cumulative the energy from each pair of aerials in said intermediate or auxiliary feeders, and means for rendering the energy so obtained cumulative in said single terminal tank circuit.

5. A wireless system comprising a plurality of pairs of aerials, means comprising twin transformers the primaries of which are connected to the aerials and so arranged that their secondary windings, connected in series through a capacity, add vectorially the voltages fed to them by the aerials, means for rendering cumulative the energy obtained from the twin transformers and means for feeding the energy so obtained to a receiving circuit. 7

6. A wireless system comprising a plurality of pairs of aerials, an inductance in each of said aerials, a twin transformer having a pair of primaries, and a pair of secondaries, associated with each pair of aerials, connecting means between each ofsaid primaries and one of said aerials, a second transformer having a'plurality of primaries and secondaries, means for connecting each pair of secondaries of said first named transformers in series with a primary winding of said last named transformers, a tank circuit, and means connecting the secondariesof aid last named transformers in series with the input of said tank circuit.

T. A w relesssystem comprising a plurality of pairs of aerials, intermediate or auxiliary feeders, an auto-transformer associated with each of said aerials, means comprising twin transformers for rendering cumulative the energy from each pair of aerials'in said intermediate or auxiliary feeders the surge impedance of which is matched to the surge impedance of the aerials and auto-transformers, means for rendering cumulative the energy from pairs of intermediate and auxiliary feeders; a tank circuit; and main feeders, the surge impedance of which is matched to the surge impedance of said intermediate or auxiliary feeders connecting said last named means to the tank circuit.

GASTON ADELIN MATHIEU. 

